Vol- XXV"| Correspondence. 247 



when the work was begun, to date. These include 'Bulletins' (Nos. 1- 

 31), 'North American Fauna' (Nos. 1-26, excepting No. 6, not yet issued), 

 'Circulars' (Nos. 1-62), 'Farmers' Bulletins' (10 in niunber), and reprints 

 of articles from the ' Yearbook ' (29 in number) . 



A more popular review of the work of the Biological Survey has also 

 recently appeared in the 'National Geographic Magazine,'^ where Mr. 

 H. W. Henshaw attractively presents the results and methods of its various 

 lines of research. Especial reference is made to the relation of birds to 

 agriculture, and the investigation made accurately to detemiine them; 

 also the losses due to small mammal pests and to wolves; bird reservations 

 and game refuges; protection of game and birds; supervision against 

 the importation of undesirable and dangerous mammals and birds. No 

 one can fail, on reading either of these documents, to realize, at least in 

 some degree, the great economic importance to the entire nation of the 

 work of the Biological Survey. — J. A. A. 



CORRESPONDENCE. 

 The BuSel-head Duck. 



Editors of 'The Auk': — 



Dear Sirs: — In the current descriptions of the colors of the adult male 

 Buffel-head Duck, there is, according to my own examination of speci- 

 mens, an error as to the color of his belly. Audubon, Chapman, Saunders, 

 Hoffman and Mrs. Bailey all include this part with the neck, breast and 

 wing-coverts, simply stating that all these are white. Wilson, alone, 

 always so exquisitely accurate in description, says: "... .rest of the scapu- 

 lars, lateral band along the wing, and whole breast, snowy white; belly, 

 vent and tail-coverts dusky white" (the italics are mine). 



This, as I have said above, agrees with my own examination of a small 

 number of specimens procured in the New York market in winter, except 

 that in my specimens the "dusky white" of the belly does not include the 

 vent, or adjacent tail-coverts, both of these tracts being pure white, or very 

 near it. In mine, too, the "dusky white "is too dark to be called any 

 kind of white. It is a delicate real pattern of wood ash color, strongest 

 along the sides and between the legs. 



Yours very truly, 



Abbott H. Thayer. 

 Monadnock, N. H., 

 Jan. 28, 1908. 



1 The Policemen of the Air. By Henry Wetherbee Henshaw. National Geo- 

 graphic Magazine, Vol. XIX, No. 2, February, 1908, pp. 79-118, with 16 full-page 

 half-tone illustrations and many others in the text. 



